Here is a geekily precise specialist documentary presented by Keanu Reeves, interviewing a range of film-makers including David Lynch and Martin Scorsese, on the relentless march of digital technology. Is film dead? And should we care? It zooms in on the technical trees, but maybe sometimes fails to pull back and look at the forest of larger issues: has digital made a real difference to the quality or quantity of movies available to regular cinemagoers? Certainly, the staggering advances in quality, affordability and portability have made a difference to film-makers, summed up by Steven Soderbergh here: "I wanted to call Film and say: 'I met someone.'"

Digital caused some startling novelties at the beginning of the last decade, such as the Dogme 95 movement, and the cinematographer Anthony Dod Mantle pioneeringly used small digital cameras for his athletic, guerrilla-style work on Festen, 28 Days Later and Slumdog Millionaire. On a grander scale, James Cameron used digital to reinvent 3D. But other film-makers are sticking with film, like Christopher Nolan, whose movies look super-contemporary and newer-than-new. So audiences could be forgiven for being baffled as to what the conclusion is. Perhaps digital is simply what is causing cinema to survive: its lowered costs are matching the lowered income-stream caused by the web and changing consumption patterns.